The number 71428
71428 is a composite number with 12 divisors. Its prime factorisation is × 7 × 2551. Divisors (12): 1, 2, 4, 7, 14, 28, 2551, 5102, 10204, 17857, 35714, 71428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
71428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
71428 is composite. Its prime factorisation is
- 3
The divisors add up to 142912; without 71428 itself that is 71484, so 71428 is abundant (71484 is more than 71428). Euler's totient φ(71428) = 30600 numbers up to 71428 share no factor with it.
- 4
The digits of 71428 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71428 = 2^{2} \times 7 \times 2551 \]71428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 142912 |
| Euler totient φ(n) | 30600 |
| Square | 5101959184 |
| Cube | 364422740594752 |
| Square root | 267.260173 (= 2√17857) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.1428 × |
71428 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand four hundred and twenty-eight |
| Binary (base 2) | 10001011100000100 |
| Octal (base 8) | 213404 |
| Hexadecimal (base 16) | 11704 |
| Base 3 | 10121222111 |
| As time | 71428 seconds = 19 h 50 min 28 s |
Is 71428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71428 ÷ 2 = 35714) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (71428 ÷ 4 = 17857) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (71428 ÷ 7 = 10204) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 71428 a prime number?
No. 71428 = × 7 × 2551, so it is divisible by 2.
What are the factors of 71428?
1, 2, 4, 7, 14, 28, 2551, 5102, 10204, 17857, 35714, 71428.
What is 71428 in binary?
10001011100000100 (hexadecimal 11704, octal 213404).
What is the square root of 71428?
About 267.2602, exactly 2√17857.
Is 71428 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 71428?
It is a composite number with 12 divisors.